Capacity of Human Neutrophils to Kill Mycobacterium tuberculosis

Although Mycobacteriun tuberculosis causes classic granulomatous lesions, neutrophils are among the first cells to arrive at the site of infection. Neutrophils from patients with active tuberculosis have been reported to have increased adherence increased nonspecific phagocytosis, and the ability to reduce blue tetrazolium. Under conditions analogous to the myeloperoxidase (MPO)-H sub(2)O sub(2)-halide system described by Klebanoff, susceptibility of M. tuberculosis) to oxidative killing has also been reported. The authors used the radiometric assay of Middlebrook to evaluate neutrophil-mediated killing of M. tuberculosis Their study showed that neutrophils were able to kill both avirulent and virulent variants of M. tuberculosis and that killing was enhanced by stimulating the neutrophils. In a cell-free system, the combination of MPO, H sub(2)O sub(2), and Cl super(-) had no more tuberculocidal activity than did H sub(2)O sub(2) alone.